Thermally rugged power amplifiers and related methods

ABSTRACT

Thermally rugged power amplifiers and related methods. In some embodiments, a method for manufacturing a radio-frequency amplifier can include providing or forming a semiconductor substrate, and forming an array of cascoded devices on the semiconductor substrate to be capable of amplifying a signal, such that the array of cascoded devices includes a plurality of cascoded devices arranged in a first row and a plurality of cascoded devices arranged in a second row. Each cascoded device can include an input stage and an output stage arranged in a cascode configuration, and each of the first and second rows can be configured such that the output stages are positioned in a staggered orientation. The staggered arrangement of the cascoded devices in the first row can be offset relative to the staggered arrangement of the cascoded devices in the second row to avoid a direct row-to-row adjacent pair of output stages.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57. Thisapplication is a continuation of U.S. application Ser. No. 15/043,556filed Feb. 13, 2016, entitled POWER AMPLIFIER HAVING STAGGERED CASCODELAYOUT FOR ENHANCED THERMAL RUGGEDNESS, which claims priority to U.S.Provisional Application No. 62/116,509 filed Feb. 15, 2015, entitledPOWER AMPLIFIER HAVING STAGGERED CASCODE LAYOUT FOR ENHANCED THERMALRUGGEDNESS, and U.S. Provisional Application No. 62/116,508 filed Feb.15, 2015, entitled CASCODE AMPLIFIER SEGMENTATION FOR ENHANCED THERMALRUGGEDNESS, the benefits of the filing dates of which are hereby claimedand the disclosures of which are hereby expressly incorporated byreference herein in their entirety.

BACKGROUND Field

The present disclosure relates to power amplifiers for radio-frequency(RF) applications.

Description of the Related Art

In many radio-frequency (RF) applications, an RF signal to betransmitted is typically amplified by a power amplifier. Such a poweramplifier can generate heat and/or be affected by heat.

SUMMARY

According to a number of implementations, the present disclosure relatesto a radio-frequency (RF) amplifier that includes an input node and anoutput node configured to receive an RF signal and provide an amplifiedRF signal, respectively. The RF amplifier further includes an array ofcascoded devices implemented between the input node and the output nodeto generate the amplified RF signal. Each cascoded device includes acommon emitter transistor and a common base transistor arranged in acascode configuration. The array is configured such that the common basetransistors are positioned in a staggered orientation relative to eachother.

In some embodiments, the staggered orientation of the common basetransistors can provide an increase in a nearest pair spacing, whencompared to a non-staggered orientation. The common base transistor canbe configured to handle more power than the common emitter transistor.The increased spacing can result in a smaller rise in temperature due tothe operation of the RF amplifier, when compared to the non-staggeredorientation. The rise in temperature resulting from the staggeredorientation can be less than half of the rise in temperature resultingfrom the non-staggered orientation.

In some embodiments, the cascoded devices can be electrically connectedin parallel such that each of the input node and the output node is arespective common node for the cascoded devices.

In some embodiments, the array of cascoded devices can include aplurality of cascoded devices arranged in the staggered orientation in afirst row. The plurality of cascoded devices in the first row can beelectrically connected in parallel. The plurality of cascoded devices inthe first row can be coupled to a common input and a common output.

In some embodiments, the array of cascoded devices can further include aplurality of cascoded devices arranged in the staggered orientation in asecond row. The staggered arrangement of cascoded devices in the firstrow and the staggered arrangement of cascoded devices in the second rowcan be offset to avoid direct row-to-row adjacent pair of common basetransistors. The plurality of cascoded devices in each row can becoupled to a common input and a common output.

In some embodiments, each cascoded device can be configured such that abase of the common emitter transistor is coupled to the input node, acollector of the common emitter transistor is coupled to an emitter ofthe common base transistor, and a collector of the common basetransistor is coupled to the output node. A base of the common basetransistor can be coupled to an emitter of the common emitter transistorthrough a bypass capacitance.

In some embodiments, the RF amplifier can be a power amplifier (PA). Insome embodiments, the PA can be configured to operate with ahigh-voltage supply.

In some teachings, the present disclosure relates to a semiconductor diethat includes a substrate, and a power amplifier (PA) implemented on thesubstrate and configured to receive and amplify a radio-frequency (RF)signal. The PA includes an array of cascoded devices implemented betweenan input node and an output node. Each cascoded device includes a commonemitter transistor and a common base transistor arranged in a cascodeconfiguration. The array is configured such that the common basetransistors are positioned in a staggered orientation relative to eachother.

In a number of implementations, the present disclosure relates to aradio-frequency (RF) module that includes a packaging substrateconfigured to receive a plurality of components, and a poweramplification system implemented on the packaging substrate. The poweramplification system includes a power amplifier (PA) configured toreceive and amplify a radio-frequency (RF) signal. The PA includes aninput node and an output node configured to facilitate the amplificationof the RF signal. The PA further includes an array of cascoded devicesimplemented between the input node and the output node. Each cascodeddevice includes a common emitter transistor and a common base transistorarranged in a cascode configuration. The array is configured such thatthe common base transistors are positioned in a staggered orientationrelative to each other.

In some embodiments, the RF module can be a power amplifier module. Insome embodiments, the RF module can be a front-end module.

In accordance with a number of implementations, the present disclosurerelates to a wireless device that includes a transceiver configured togenerate a radio-frequency (RF) signal, and a front-end module (FEM) incommunication with the transceiver. The FEM includes a packagingsubstrate configured to receive a plurality of components, and a PAconfigured to amplify the RF signal. The PA includes an input node andan output node configured to facilitate the amplification of the RFsignal. The PA further includes an array of cascoded devices implementedbetween the input node and the output node. Each cascoded deviceincludes a common emitter transistor and a common base transistorarranged in a cascode configuration. The array is configured such thatthe common base transistors are positioned in a staggered orientationrelative to each other. The wireless device further includes an antennain communication with the FEM. The antenna is configured to transmit theamplified RF signal.

In some embodiments, the wireless device can be, for example, a cellularphone.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a wireless system or architecture that includes anamplification system.

FIG. 2 shows that the amplification system of FIG. 1 can include aradio-frequency (RF) amplifier assembly having one or more poweramplifiers (PAs).

FIGS. 3A-3E show examples of how the PA of FIG. 2 can be configured.

FIG. 4 shows that in some embodiments, the amplification system of FIG.2 can be implemented as a high-voltage (HV) power amplification system.

FIG. 5 shows an example of an array of cascoded devices, where eachcascoded device includes an RF transistor and a cascode transistor.

FIG. 6 depicts an example of a physical layout of an array, where theorientations of two cascoded devices are the same.

FIG. 7 depicts an example physical layout of an array, where onecascoded device has an inverted orientation relative to an adjacentcascoded device, so as to form a staggered configuration.

FIG. 8 shows that an array can include more than two cascoded devices.

FIG. 9 shows that an array can include more than one row of cascodeddevices so as to yield a two-dimensional arrangement.

FIG. 10 shows an example layout that is similar to the block diagramrepresentation of FIG. 6.

FIG. 11 shows an example of a two-dimensional array that is based on thenon-staggered configuration of FIG. 6.

FIG. 12 shows another view of the two-dimensional array of FIG. 11.

FIG. 13 shows temperature profiles at an example spacing between cascodetransistors in the two-dimensional array of FIG. 12.

FIG. 14 shows an example layout that is similar to the block diagramrepresentation of FIG. 7.

FIG. 15 shows an example of a two-dimensional array that is based on thestaggered configuration of FIG. 7.

FIG. 16 shows another view of the two-dimensional array of FIG. 15.

FIG. 17 shows temperature profiles at an example spacing between cascodetransistors in the two-dimensional array of FIG. 16.

FIG. 18 shows a comparison of areas associated with non-staggered andstaggered arrays.

FIG. 19 shows that in some embodiments, some or all of a PA array havingone or more features as described herein can be implemented in a module.

FIG. 20 depicts an example wireless device having one or moreadvantageous features described herein.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

The headings provided herein, if any, are for convenience only and donot necessarily affect the scope or meaning of the claimed invention.

Referring to FIG. 1, one or more features of the present disclosuregenerally relate to a wireless system or architecture 50 having anamplification system 52. In some embodiments, the amplification system52 can be implemented as one or more devices, and such device(s) can beutilized in the wireless system/architecture 50. In some embodiments,the wireless system/architecture 50 can be implemented in, for example,a portable wireless device. Examples of such a wireless device aredescribed herein.

FIG. 2 shows that the amplification system 52 of FIG. 1 typicallyincludes a radio-frequency (RF) amplifier assembly 54 having one or morepower amplifiers (PAs). In the example of FIG. 2, three PAs 60 a-60 care depicted as forming the RF amplifier assembly 54. It will beunderstood that other numbers of PA(s) can also be implemented. It willalso be understood that one or more features of the present disclosurecan also be implemented in RF amplifier assemblies having other types ofRF amplifiers.

In some embodiments, the RF amplifier assembly 54 can be implemented onone or more semiconductor die, and such die can be included in apackaged module such as a power amplifier module (PAM) or a front-endmodule (FEM). Such a packaged module is typically mounted on a circuitboard associated with, for example, a portable wireless device.

The PAs (e.g., 60 a-60 c) in the amplification system 52 are typicallybiased by a bias system 56. Further, supply voltages for the PAs aretypically provided by a supply system 58. In some embodiments, either orboth of the bias system 56 and the supply system 58 can be included inthe foregoing packaged module having the RF amplifier assembly 54.

In some embodiments, the amplification system 52 can include a matchingnetwork 62. Such a matching network can be configured to provide inputmatching and/or output matching functionalities for the RF amplifierassembly 54.

For the purpose of description, it will be understood that each PA (60)of FIG. 2 can be implemented in a number of ways. FIGS. 3A-3E shownon-limiting examples of how such a PA can be configured. FIG. 3A showsan example PA having an amplifying transistor 64, where an input RFsignal (RF_in) is provided to a base of the transistor 64, and anamplified RF signal (RF_out) is output through a collector of thetransistor 64.

FIG. 3B shows an example PA having a plurality of amplifying transistors(e.g., 64 a, 64 b) arranged in stages. An input RF signal (RF_in) isprovided to a base of the first transistor 64 a, and an amplified RFsignal from the first transistor 64 a is output through its collector.The amplified RF signal from the first transistor 64 a is provided to abase of the second transistor 64 b, and an amplified RF signal from thesecond transistor 64 b is output through its collector to thereby yieldan output RF signal (RF_out) of the PA.

In some embodiments, the foregoing example PA configuration of FIG. 3Bcan be depicted as two or more stages as shown in FIG. 3C. The firststage 64 a can be configured as, for example, a driver stage; and thesecond stage 64 b can be configured as, for example, an output stage.

FIG. 3D shows that in some embodiments, a PA can be configured as aDoherty PA. Such a Doherty PA can include amplifying transistors 64 a,64 b configured to provide carrier amplification and peakingamplification of an input RF signal (RF_in) to yield an amplified outputRF signal (RF_out). The input RF signal can be split into the carrierportion and the peaking portion by a splitter. The amplified carrier andpeaking signals can be combined to yield the output RF signal by acombiner.

FIG. 3E shows that in some embodiments, a PA can be implemented in acascode configuration. An input RF signal (RF_in) can be provided to abase of the first amplifying transistor 64 a operated as a commonemitter device. The output of the first amplifying transistor 64 a canbe provided through its collector and be provided to an emitter of thesecond amplifying transistor 64 b operated as a common base device. Theoutput of the second amplifying transistor 64 b can be provided throughits collector so as to yield an amplified output RF signal (RF_out) ofthe PA.

In the various examples of FIGS. 3A-3E, the amplifying transistors aredescribed as bipolar junction transistors (BJTs) such as heterojunctionbipolar transistors (HBTs). It will be understood that one or morefeatures of the present disclosure can also be implemented in or withother types of transistors such as field-effect transistors (FETs).

FIG. 4 shows that in some embodiments, the amplification system 52 ofFIG. 2 can be implemented as a high-voltage (HV) power amplificationsystem 70. Such a system can include an HV power amplifier assembly 54configured to include HV amplification operation of some or all of thePAs (e.g., 60 a-60 c). As described herein, such PAs can be biased by abias system 56. In some embodiments, the foregoing HV amplificationoperation can be facilitated by an HV supply system 58. In someembodiments, an interface system 72 can be implemented to provideinterface functionalities between the HV power amplifier assembly 54 andeither or both of the bias system 56 and the HV supply system 58.

High thermal dissipation within radio-frequency (RF) power arrays, suchas power amplifier (PA) arrays, typically requires sufficient spacing ofadjacent elements for ruggedness and device reliability. Such spacingtypically requires larger die size which in turn results in higher costimplementations.

Described herein are examples related to reduction of die temperatureswithout necessarily requiring an increase in die size. Such anadvantageous feature can be achieved by selected placement of highthermal dissipation devices within a given array. In the context of acascode PA array, it is noted that such an array typically includeslower temperature RF devices (also referred to herein as common emitter(CE) devices) and higher temperature cascode devices (also referred toherein as common base (CB) devices). Thus, a stagger arrangement of theRF and cascode transistors can be implemented such that one hightemperature device is not directly adjacent to another high temperaturedevice.

FIG. 5 shows an example of an array 100 of cascoded devices, where eachcascoded device 102 includes an RF transistor 110 (also referred toherein as a CE device) and a cascode transistor 112 (also referred toherein as a CB device). Among others, examples of how such an array canbe implemented are described in U.S. Provisional Application No.62/116,508 filed Feb. 15, 2015, entitled CASCODE AMPLIFIER SEGMENTATIONFOR ENHANCED THERMAL RUGGEDNESS, the disclosure of which is herebyexpressly incorporated by reference herein in its entirety.

In the example of FIG. 5, the array 100 is shown to include two cascodeddevices 102, 102′. It will be understood that more than two cascodeddevices can be arranged in a similar manner.

Referring to FIG. 5, each of the cascoded device (102 or 102′) is shownto include a common emitter (CE) device (110 or 110′) (also referred toherein as an RF transistor) coupled to a common base (CB) device (112 or112′) (also referred to herein as a cascode transistor). The emitter ofthe RF transistor (110 or 110′) is shown to be coupled to the base ofthe cascode transistor (112 or 112′) through a cascode bypasscapacitance (C2 or C2′). The emitter of the RF transistor (110 or 110′)can be coupled to ground (128 or 128′).

In the example array 100 of FIG. 5, each cascoded device can include itsown bias circuits for the RF transistor and the cascode transistor. Moreparticularly, the RF transistor 110 of the first cascoded device 102 isshown to have a input bias circuit 140 coupled to its base, and thecascode transistor 112 is shown to have a cascode bias circuit 150coupled to its base. Similarly, the RF transistor 110′ of the secondcascoded device 102′ is shown to have an input bias circuit 140′ coupledto its base, and the cascode transistor 112′ is shown to have a cascodebias circuit 150′ coupled to its base.

In the example of FIG. 5, at least some portions of the input biascircuits 140, 140′ can be coupled to facilitate, for example, a commonRF input (RF_in). Similarly, the collectors 132, 132′ of the cascodetransistors 112, 112′ can be coupled to yield a common RF output(RF_out), and to receive a common supply voltage.

In some embodiments, the array of cascoded devices of FIG. 5 can beimplemented so as to yield isolated connections between the parallelelements. For example, the array can be built with a plurality of CE(110)/CB (112) pairs, instead of building a separate CE array and aseparate CB array.

FIG. 6 depicts an example of a physical layout of an array 100, wherethe orientations of two cascoded devices are the same. Accordingly, thecascode transistors 112 of the two adjacent cascoded devices are shownto be directly adjacent to each other. The example physical layout ofFIG. 6 can represent the example of FIG. 5, if the two cascoded devices102, 102′ are physically laid out as shown in the circuitrepresentation.

FIG. 7 depicts an example physical layout of an array 100, where onecascoded device has an inverted orientation relative to an adjacentcascoded device, so as to form a staggered configuration. Accordingly,the cascode transistor 112 of one cascoded device (e.g., upper portionof the cascoded device on the left) is at a diagonal orientationrelative to the cascode transistor 112 of the adjacent cascoded device(e.g., lower portion of the cascoded device on the right). It is notedthat the distance between such diagonally arranged cascode transistors112 is greater than the distance between the directly adjacent cascodetransistors 112 of FIG. 6, if all other dimensions remain generally thesame.

FIG. 8 shows that an array 100 can include more than two cascodeddevices. Such cascoded devices can be arranged as a continuation of thestaggered configuration of the example of FIG. 7. Accordingly, it isnoted that each cascode transistor 112 is at a diagonal arrangementrelative to another cascode transistor 112 of an adjacent cascodeddevice.

In the foregoing example of FIG. 8, one row of cascoded devices areshown. FIG. 9 shows that an array 100 can include more than one row ofcascoded devices so as to yield a two-dimensional arrangement. In such atwo-dimensional arrangement, a given row (e.g., such as the row of FIG.8) can have an offset arrangement with an adjacent row, such thatbetween such two rows, there is no direct row-to-row adjacent pair ofcascode transistors 112.

FIG. 10 shows an example layout that is similar to the block diagramrepresentation of FIG. 6. FIGS. 11 and 12 show an example of atwo-dimensional array that is based on the non-staggered configurationof FIG. 6. FIG. 14 shows an example layout that is similar to the blockdiagram representation of FIG. 7, in which the cascode transistors arein a staggered configuration. FIGS. 15 and 16 show an example of atwo-dimensional array that is based on the staggered configuration ofFIG. 7. In the examples shown, various values such as dimensions areshown. It will be understood that such values are examples, and thatother values can be utilized.

For the purpose of comparing the foregoing non-staggered and staggeredconfigurations, it will be understood that dimensions associated with agiven cascoded device (whether in non-staggered or staggeredarrangement) generally remain the same. For example, each RF transistorhas an area of approximately 40 μm², each cascode transistor has a muchlarger area of approximately 160 μm², and the center-to-center spacingbetween two directly adjacent cascode transistors is approximately 55μm.

As stated above, two cascode transistors are spaced at approximately 55μm when in a direct adjacent configuration (e.g., see FIG. 10). When ina diagonal configuration resulting from a staggered configuration,center-to-center spacing between the cascode transistors of two adjacentcascode devices is approximately 100 μm (e.g., see FIG. 14) which isalmost twice the 55 μm separation.

Accordingly, the two-dimensional array of FIGS. 15 and 16 (having thestaggered and row-offset configuration) is expected to have betterthermal dissipation property than the two-dimensional array of FIGS. 11and 12 (having the direct adjacent configuration within a given row).FIGS. 13 (direct adjacent configuration) and 17 (staggered androw-offset configuration) show that such is indeed true. Compared toabout 4 degree C. rise in temperature (FIG. 13) due to the 55 μm spacingof the direct adjacent configuration, the staggered and row-offsetconfiguration yields a temperature rise that is less than 2 degree C.(FIG. 17) due to the 100 μm spacing.

Referring to FIGS. 11 (direct adjacent configuration) and 15 (staggeredand row-offset configuration), one can see that the latter configurationcan yield narrower but taller dimensions compared to the formerconfiguration. In some embodiments, such narrower dimension can beallowed due to the stagger configuration in which two cascoded devicescan be brought closer together without the cascode transistors becomingtoo close. In some embodiments, such taller dimension can facilitate RFsignal input and biasing connections associated with the row-offsetconfiguration.

FIG. 18 shows a comparison of areas of the two foregoing example arrays,as well as an array of common emitters. One can see that the staggeredcascode array on the left has an overall area that is similar to thearea of the non-staggered array in the center.

For the purpose of description, it will be understood that an array caninclude a plurality of units (e.g., cascoded devices) arranged in one ormore rows and/or columns. Thus, an array can include a plurality ofunits arranged in a single row, such as in the examples of FIGS. 7, 8and 14. An array can also include a plurality of units arranged in aplurality of rows, such as in the examples of FIGS. 9, 15 and 16.

It will also be understood that in an array of cascoded devices, eachcascoded device can have a separate input and a separate output for anRF signal, a common input and a common output for each of a plurality ofgroups of cascoded devices, a common input and a common output for allof the cascoded devices in the array, or any combination thereof. Forexample, in the example of FIG. 15, each row of three cascoded devicescan be arranged in an electrically parallel manner, sharing a commoninput and a common output for an RF signal. Thus, in such an examplecontext, the two-dimensional array of nine cascoded devices can providethree separate amplification paths.

In some embodiments, an array of cascoded devices having one or morefeatures as described herein can be implemented on a semiconductor die.For example, the array of cascoded devices of FIGS. 15 and 16 can beimplemented on a single semiconductor die.

FIG. 19 shows that in some embodiments, one or more features associatedwith a cascode architecture as described herein (e.g., array 100 inFIGS. 7-9 and 14-16) can be implemented in a module. Such a module canbe, for example, a front-end module (FEM). In the example of FIG. 19, amodule 300 can include a packaging substrate 302, and a number ofcomponents can be mounted on such a packaging substrate. For example, anFE-PMIC component 304, a power amplifier assembly 306, a match component308, and a duplexer assembly 310 can be mounted and/or implemented onand/or within the packaging substrate 302. Other components such as anumber of SMT devices 314 and an antenna switch module (ASM) 312 canalso be mounted on the packaging substrate 302. Although all of thevarious components are depicted as being laid out on the packagingsubstrate 302, it will be understood that some component(s) can beimplemented over other component(s).

In some implementations, a device and/or a circuit having one or morefeatures described herein can be included in an RF device such as awireless device. Such a device and/or a circuit can be implementeddirectly in the wireless device, in a modular form as described herein,or in some combination thereof. In some embodiments, such a wirelessdevice can include, for example, a cellular phone, a smart-phone, ahand-held wireless device with or without phone functionality, awireless tablet, etc.

FIG. 20 depicts an example wireless device 400 having one or moreadvantageous features described herein. In the context of a modulehaving one or more features as described herein, such a module can begenerally depicted by a dashed box 300, and can be implemented as, forexample, a front-end module (FEM). Such a module can include an array100 of cascoded devices as described herein.

Referring to FIG. 20, power amplifiers (PAs) 420 can receive theirrespective RF signals from a transceiver 410 that can be configured andoperated in known manners to generate RF signals to be amplified andtransmitted, and to process received signals. The transceiver 410 isshown to interact with a baseband sub-system 408 that is configured toprovide conversion between data and/or voice signals suitable for a userand RF signals suitable for the transceiver 410. The transceiver 410 canalso be in communication with a power management component 406 that isconfigured to manage power for the operation of the wireless device 400.Such power management can also control operations of the basebandsub-system 408 and the module 300.

The baseband sub-system 408 is shown to be connected to a user interface402 to facilitate various input and output of voice and/or data providedto and received from the user. The baseband sub-system 408 can also beconnected to a memory 404 that is configured to store data and/orinstructions to facilitate the operation of the wireless device, and/orto provide storage of information for the user.

In the example wireless device 400, outputs of the PAs 420 are shown tobe matched (via respective match circuits 422) and routed to theirrespective duplexers 420. Such amplified and filtered signals can berouted to an antenna 416 through an antenna switch 414 for transmission.In some embodiments, the duplexers 420 can allow transmit and receiveoperations to be performed simultaneously using a common antenna (e.g.,416). In FIG. 20, received signals are shown to be routed to “Rx” pathsthat can include, for example, a low-noise amplifier (LNA).

A number of other wireless device configurations can utilize one or morefeatures described herein. For example, a wireless device does not needto be a multi-band device. In another example, a wireless device caninclude additional antennas such as diversity antenna, and additionalconnectivity features such as Wi-Fi, Bluetooth, and GPS.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Additionally, the words “herein,” “above,” “below,” and words of similarimport, when used in this application, shall refer to this applicationas a whole and not to any particular portions of this application. Wherethe context permits, words in the above Description using the singularor plural number may also include the plural or singular numberrespectively. The word “or” in reference to a list of two or more items,that word covers all of the following interpretations of the word: anyof the items in the list, all of the items in the list, and anycombination of the items in the list.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While some embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. A method for manufacturing a radio-frequencyamplifier, the method comprising: providing or forming a semiconductorsubstrate; and forming an array of cascoded devices on the semiconductorsubstrate to be capable of amplifying a signal, such that the array ofcascoded devices includes a plurality of cascoded devices arranged in afirst row and a plurality of cascoded devices arranged in a second row,each cascoded device including an input stage and an output stagearranged in a cascode configuration, each of the first and second rowsconfigured such that the output stages are positioned in a staggeredorientation, the staggered arrangement of the cascoded devices in thefirst row offset relative to the staggered arrangement of the cascodeddevices in the second row to avoid a direct row-to-row adjacent pair ofoutput stages.
 2. The method of claim 1 wherein the input stage includesa common emitter transistor, and the output stage includes a common basetransistor.
 3. The method of claim 1 wherein at least some of thecascoded devices are electrically connected in parallel.
 4. The methodof claim 3 wherein the plurality of cascoded devices in the first roware electrically connected in parallel.
 5. The method of claim 4 whereinthe plurality of cascoded devices in the second row are electricallyconnected in parallel.
 6. The method of claim 1 wherein the plurality ofcascoded devices in each of the first row and the second row are coupledto a common input and a common output.
 7. The method of claim 1 whereinthe radio-frequency amplifier is a power amplifier configured to operatewith a high-voltage supply.
 8. A radio-frequency amplifier comprising: asemiconductor substrate; and an array of cascoded devices implemented onthe semiconductor substrate and capable of amplifying a signal, thearray of cascoded devices including a plurality of cascoded devicesarranged in a first row and a plurality of cascoded devices arranged ina second row, each cascoded device including an input stage and anoutput stage arranged in a cascode configuration, each of the first andsecond rows configured such that the output stages are positioned in astaggered orientation, the staggered arrangement of the cascoded devicesin the first row offset relative to the staggered arrangement of thecascoded devices in the second row to avoid a direct row-to-row adjacentpair of output stages.
 9. The radio-frequency amplifier of claim 8wherein the input stage includes a common emitter transistor, and theoutput stage includes a common base transistor.
 10. The radio-frequencyamplifier of claim 8 wherein the staggered orientation of the outputstages provide an increase in a nearest pair spacing in thecorresponding row, when compared to a non-staggered orientation.
 11. Theradio-frequency amplifier of claim 10 wherein the output stage isconfigured to handle more power than the corresponding input stage. 12.The radio-frequency amplifier of claim 10 wherein the increased spacingresults in a smaller rise in temperature due to the operation of theradio-frequency amplifier, when compared to the non-staggeredorientation.
 13. The radio-frequency amplifier of claim 12 wherein therise in temperature resulting from the staggered orientation is lessthan half of the rise in temperature resulting from the non-staggeredorientation.
 14. The radio-frequency amplifier of claim 8 wherein atleast some of the cascoded devices are electrically connected inparallel.
 15. The radio-frequency amplifier of claim 14 wherein theplurality of cascoded devices in the first row are electricallyconnected in parallel.
 16. The radio-frequency amplifier of claim 15wherein the plurality of cascoded devices in the second row areelectrically connected in parallel.
 17. The radio-frequency amplifier ofclaim 8 wherein the plurality of cascoded devices in each of the firstrow and the second row are coupled to a common input and a commonoutput.
 18. The radio-frequency amplifier of claim 8 wherein theradio-frequency amplifier is a power amplifier configured to operatewith a high-voltage supply.
 19. A semiconductor die comprising: asubstrate; and an amplifier implemented on the substrate and configuredto amplify a signal, the amplifier including an array of cascodeddevices having a plurality of cascoded devices arranged in a first rowand a plurality of cascoded devices arranged in a second row, eachcascoded device including an input stage and an output stage arranged ina cascode configuration, each of the first and second rows configuredsuch that the output stages are positioned in a staggered orientation,the staggered arrangement of the cascoded devices in the first rowoffset relative to the staggered arrangement of the cascoded devices inthe second row to avoid a direct row-to-row adjacent pair of outputstages.
 20. The semiconductor die of claim 19 wherein the amplifier isconfigured as a power amplifier.